Clutch and Throw Out Bearing Details

 1. What is a Clutch?

The clutch is the core component of a manual transmission system in an automobile, located between the engine and the transmission. Its main function is to control the connection and disconnection between the engine and the transmission system under the driver's operation, allowing the vehicle to start smoothly, shift gears, and cut off the power transmission from the engine to the wheels without interrupting the power.

 The basic working principle of the clutch:

- Clutch disk: located between the flywheel and pressure plate, transmits power from the engine to the transmission through friction.

- Pressure plate: pressure is exerted through a spring or diaphragm spring to bring the clutch disk into close contact with the flywheel and transmit power.

- Flywheel: Fixed to the engine crankshaft, it provides a stable rotating surface in contact with the clutch disk.

When the driver depresses the clutch pedal, the clutch pressure plate moves away from the clutch disk, disconnecting the power connection between the engine and transmission; when the clutch pedal is released, the pressure plate resumes contact with the clutch disk, and the power from the engine is retransmitted to the transmission to drive the wheels.

 Types and characteristics of clutches:

1. single-disc clutch: the most common type of clutch, using one clutch disc, widely used in small cars and some light commercial vehicles.

2. Double plate clutch: Suitable for higher power engines, usually used in heavy duty trucks, racing cars and high performance automobiles. It is able to withstand greater loads than single disc clutches.

3. Hydraulic Drive Clutch: It realizes the power disconnection between the engine and transmission through the hydraulic torque converter, and is usually used in automatic transmission (AT) models.

4. Self-adjusting clutches: with self-adjusting function, the clutch gap can be adjusted automatically, which reduces the need for maintenance.

 Main features of the clutch:

- Control of power transmission: Controls the connection and disconnection of power when shifting gears.

- Transmits torque: the clutch transmits engine torque to the gearbox through friction.

- Reduces wear and tear: The clutch engages and disengages smoothly, avoiding shocks between the engine and the transmission.

 2. What is a clutch release bearing?

A clutch release bearing, also known as a clutch throwout bearing or release bearing, is an important component in the clutch system. It is located between the clutch pressure plate and the release fork (or release lever). When the driver depresses the clutch pedal, the release bearing is pushed forward to make contact with the back of the clutch pressure plate and exerts pressure, causing the clutch pressure plate to separate from the clutch disk, thus disconnecting the power transmission between the engine and the transmission.

 The basic operating principle of the clutch release bearing:

- When the driver depresses the clutch pedal, the hydraulic system or mechanical linkage transmits pressure to the release bearing, causing it to move forward and push the release fork, which in turn moves the pressure plate away from the clutch disc.

- The function of the release bearing is to ensure that the pressure plate moves smoothly and that the clutch disengagement action is carried out properly, thus disconnecting the power between the engine and the gearbox.

- Clutch release bearings are usually designed as rolling bearings or plain bearings that can withstand certain loads and pressures.

 Types and characteristics of clutch release bearings:

1. rolling bearing type thrust bearing: this type of thrust bearing uses rolling elements to minimize friction and usually has a long service life and is capable of withstanding large loads.

2. Sliding bearing type thrust bearing: using the sliding friction principle, it is simpler and suitable for vehicles with smaller loads.

 Main characteristics of clutch release bearings:

- Wear resistance: Thrust bearings need to withstand constant pressure and are prone to wear and tear in long-term operation, so they need to have good wear resistance.

- Noise control: Thrust bearings must be designed to minimize noise during operation and maintain smooth clutch operation.

- High Temperature Resistance: Since the clutch system generates a large amount of heat, thrust bearings need to have good resistance to high temperatures.

 3. Relationship and Collaboration between Clutch and Throw Out Bearing

Clutch and Throw Out Bearing are two components that work closely together and play a vital role in the vehicle's power transmission system. Their relationship can be understood in the following ways:

- Working in tandem: The clutch and thrust bearing work in tandem. When the driver depresses the clutch pedal, the thrust bearing pushes the pressure plate between the pressure plate and the clutch disk, thus cutting off the power transmission between the engine and the gearbox and enabling the gearshift operation to be carried out smoothly.

- Interaction: The thrust bearing transmits force through the release fork, enabling the clutch pressure plate to move. The clutch pressure plate separates from the clutch disk under the action of the thrust bearing to avoid direct transmission of engine power to the gearbox.

- Power Transmission Control: The thrust bearing ensures the normal disengagement and engagement of the clutch by controlling the movement of the clutch pressure plate, so as to ensure the smooth transmission and disengagement of power. Without the support of the thrust bearing, the operation of the clutch will be affected, causing driving difficulties.

 4. Common Failures of Clutches and throw out Bearings

 Clutch malfunction:

1. Clutch slipping: Worn or oiled clutch disk leads to insufficient friction and engine power cannot be fully transmitted to the transmission.

2. Clutch stalling: incomplete clutch disengagement, possibly due to damage to the pressure plate, clutch disk or thrust bearing.

3. Clutch pedal inflexibility: problems with hydraulic system or loose clutch leads.

throw out bearing failure:

1. Throw out bearing wear: Thrust bearings may wear out due to prolonged use or insufficient lubrication, resulting in incomplete separation and noise.

2. Throw out bearing stalling: Thrust bearings may stall due to internal bearing damage or ingress of contaminants, which can affect clutch operation.

 5. Maintenance and Replacement

 Clutch system maintenance:

- Periodic Inspection: Periodically check the condition of the clutch hydraulic system, clutch disc and pressure plate to ensure proper operation.

- Maintain lubrication: Keep the clutch well lubricated to avoid excessive wear.

- Avoid pressing the clutch pedal for a long time: Reduce unnecessary friction and prolong the life of the clutch.

 Thrust bearing maintenance:

- Regular inspection: Check the wear of the thrust bearing regularly and make sure it is adequately lubricated.

- Timely replacement: If you find noise or unsmooth operation, you should replace the thrust bearing in time.

Summarize:

Clutch and clutch release bearing (Throw Out Bearing) are key components that complement each other in an automobile manual transmission. The main function of the clutch is to control the transfer of power between the engine and the transmission, while the throw out bearing ensures that the engine is disconnected from the transmission by putting pressure on the clutch pressure plate to help it separate. Their efficient collaboration ensures that the vehicle can shift gears and start smoothly, and is an indispensable part of the automotive transmission system.